Si-containing thin films are used widely in the semiconductor, photovoltaic, LCD-TFT, flat panel-type device, refractory material, or aeronautic industries. Si-containing thin films may be used, for example, as dielectric materials having electrical properties which may be insulating (SiO2, SiN, SiCN, SiCOH, MSiOx, wherein M is Hf, Zr, Ti, Nb, Ta, or Ge, and x is greater than zero), Si-containing thin films may be used as conducting films, such as metal silicides or metal silicon nitrides. Due to the strict requirements imposed by downscaling of electrical device architectures towards the nanoscale (especially below 28 nm node), increasingly fine-tuned molecular precursors are required which meet the requirements of volatility (for ALD process), lower process temperatures, reactivity with various oxidants and low film contamination, in addition to high deposition rates, conformality and consistency of films produced.
Hunks et al. disclose a wide range of Si-containing precursors in US2010/0164057, including silicon compounds having the formula R4-xSiLx, wherein x is an integer having a value from 1 to 3; R may be selected from H, branched and unbranched C1-C6 alkyl, C3-C8 cycloalkyl, and C6-C13 aryl groups; and L may be selected from isocyanato, methylethylketoxime, trifluoroacetate, triflate, acyloxy, μ-diketiminate, μ-diiminate, amidinate, guanidinate, alkylamino, hydride, alkoxide, or formate ligands. Pinnavaia et al. claim a method for the preparation of a porous synthetic, semi-crystalline hybrid organic-inorganic silicon oxide composition from silicon acetylacetonate and silicon 1,3-diketonate precursors (U.S. Pat. No. 6,465,387).
In Proceedings of SPIE 2438, Advances in Resist Technology and Processing XII, 762 (Jun. 9, 1995), Wheeler et al. disclose aminodisilanes used as silylating reagents for near-surface imaging with deep-UV (248 nm) and EUV (13.5 nm) lithography.
Disilane containing precursors bearing both alkyl and amino groups have been disclosed for deposition of SiCN thin films by Tsukada and Dussarrat in JP 2006096675.
Xiao et al. disclose another family of Si-containing precursors in US2013/0323435 which have the formula (R1R2N)n—SiH3-nSiH3 wherein R1 is selected from linear or branched C3 to C10 alkyl group, linear or branched C3 to C10 alkenyl group, linear or branched C3 to C10 alkynyl group, C1 to C6 dialkylamino group, electron withdrawing group, and C6 to C10 aryl group; R2 is selected from hydrogen, linear or branched C1 to C10 alkyl group, linear or branched C3 to C6 alkenyl group, linear or branched C3 to C6 alkynyl group, C1 to C6 dialkylamino group, C6 to C10 aryl group, linear or branched C1 to C6 fluorinated alkyl group, electron withdrawing group, and C4 to C10 aryl group; optionally wherein R1 and R2 are linked together to form ring selected from substituted or unsubstituted aromatic ring or substituted or unsubstituted aliphatic ring; and n=1 or 2.
Additionally, Xiao et al also disclose another family of Si-containing precursors in US2013/0319290 which have the formula (R1R2N)—SiH2SiH2—(NR3R4) and methods for forming silicon-containing films and wherein R1 and R3 are independently selected from linear or branched C3 to C10 alkyl group, a linear or branched C3 to C10 alkenyl group, a linear or branched C3 to C10 alkynyl group, a C1 to C6 dialkylamino group, an electron withdrawing and a C6 to C10 aryl group; R2 and R4 are independently selected from hydrogen, a linear or branched C3 to C10 alkyl group, a linear or branched C3 to C10 alkenyl group, a linear or branched C3 to C10 alkynyl group, a C1 to C6 dialkylamino group, an electron withdrawing, and a C6 to C10 aryl group; and wherein any one, all, or none of R1 and R2, R3 and R4, R1 and R3, or R2 and R4 are linked to form a ring.
Recently Dussarrat et al. disclosed silicon amidinate precursors in WO2014/015232, which have the form H3Si(amd), and silicon β-diketiminate precursors in WO2014/015237, each of which demonstrate the utility of the chelating ligand framework to support the —SiH3 functionality. The same authors also disclosed related oxygen containing precursors based upon chelating O—O and N—O delocalized ligand frameworks [see WO2014/015241 and WO2014/015248, respectively].
Sanchez et al. disclose compounds and methods of preparation of Si—X and Ge—X compounds (X═N, P, As, Sb) via dehydrogenative coupling between the corresponding unsubstituted silanes and amines (including NH3) and phosphines catalyzed by metallic catalysts (US2015/0094470).
Despite the wide range of choices available for the deposition of Si containing films, additional precursors are continuously sought to provide device engineers the ability to tune manufacturing process requirements and achieve films with desirable electrical and physical properties.